Heat exchanger



y 1934- J. o. OLSON 1,966,559

HEAT EXCHANGER Filed Nov. 22. 1950 4 Sh eets-Sheet 1 Fig.4..

-2. I Fig-3 2 0.0lson. B6 fltor-negs.

I nvento r:

July 17, 1934. J. o. OLSON 1,966,559

HEAT EXCHANGER Filed NOV. 22, 1930 4 Sheets-Sheet 2 Fig-5 Inven+orfiJohn 0. Olson.

July 17, 1934. C) QQLSON 1,966,559

HEAT EXCHANGER Filed O 22. 1950 4 Sheets-Sheet 3 Fig-8 J'ohn'O. lson. BM/MM I nve n to r:

July 17, 1934. J. o. OLSON 1,966,559

I HEAT EXCHANGER Filed Nov. 22. 1930 4 Sheets-Sheet 4 Fig-'9.

I i W; 1

HI l IiI'a HIFJIEIEILJL E L Invenl'or- John O. OLson. fjZ/WMKW KbfornegaPatented July 17, 1934 UNITED STATES PATENT o l-FlCE 1,966,559 mmEXOHANGEB John om Olson, St. Paul, Minn.

Application November 2 17 Claims.

' also adapted to use for the transfer of heat from any heating mediumto any transfer medium,

as air.

It is a principal object of my invention to provide a heat exchangerelement having a central core of cast metal in which are embedded andintegrated a multiplicity of fins of sheet metal, the free portions ofwhich extend outwardly from the cast metal core and are adapted toengage the medium to which heat is exchanged, as air or water, or otherfluid. In carrying out this object the central core may be of anydesired shape, either cylindrical, oblong or any other shape whereinthere is an enclosed cavity within the casting. The cast metal will comprise the inner layer or portion of this core, and over this is a layerof previously fabricated metal such as sheet metal or metal strips, andthe fins pass through the outer layer of previously fabricated metal andinto the cast core. Both the outer layer of previously formed metal andthe inwardly protruding portions of the fins are integrated with thecast metal core so as to become in effect a part of it. If the castmetal is the same material as the previously fabricated metal and thefins so that each have substantially the same fusing point, there willnecessarily be some degree of fusing of said ,metals with the cast metalwhich may be made more or less according to the temperature of the castmetal as poured. If, as is contemplated, the previously fabricated metaland the metal of the fins have a higher melting point than the castmetal, there will be firm'embedm'ent without fusing. Where there isfusing naturally a the edges of the .fins which are projected into thecast metal will be most largelyfused. Likewise, -since in the practiceof my invention these edges are laterally spaced one from the other,forming circumferential or longitudinal channels between adjacent pairs,it must necessarily follow that in the expansion of the cast metal as itsolidifies there will be a very firm binding and gripping of theseportions of fins within the cast metal, resulting in making themsubstantially integral with the cast metal core.

The above-defined heat exchangers are fabricated in accordance with theprocess defined in my above-noted patent and also in some specificembodiments in accordance with a process for 2, 1930, Serial No. 497,571

which application is being made on even date herewith, serial number497,570.

The full objects and advantages of my invention will appear inconnection with the detailed description thereof and the novel featuresof the invention are particularly pointed out in the claims.

In the drawings illustrating the application of my invention in some ofits-forms,

1 is a part sectional elevation view of a heat exchanger fabricated inaccordance with my above-referred-to later-filed application. Fig. 2 isa sectional plan view on reduced scale on line 2-2 of Fig, 1. Fig. 3 isa planyiew on reduced scale of one of the fin plates. Fig. 4 is a sideelevation part sectional view of one form of heat exchanger made by theprocess of my Patent 1,742,556, the sectional part being taken in twoplanes through the retaining lugs and outside of the lugs respectively.Fig. 5 is a sectional view on line 55 of Fig. -4. Fig. 6 is a sectionalview on line 66 of Fig. 4. Fig. 7 is a sectional elevation view ofanother form of heat exchanger disclosed in my aforesaid patent. Fig. 8is a sectional plan view on line 88 of Fig. 7. Fig. 9 is a view similarto Fig. 1 showing the heat exchanger adapted to direct gas firing.- Fig.10 is a view similar to Fig. 7 also showing that heat exchanger adaptedto gas firing.

As illustrated in Figs. 1, 2, 3 and 9, the heat exchanger comprises acast metal inner lining having walls 10 which may be circularor of anydesired shape in cross-section and a top wall 11 and bottom wall 12 inthe form shown in Fig. 1 through which heating medium, as water orsteam, is admitted through pipe openings 13, 14. In the form shown inFig. 9 there will be the top wall 11 and dicharge pipe 15, but no bottomwall, the entire bottom portion of the vchamber being open as indicatedat 16 to permit direct firing from gas burner 17.

Before the inner shell 10, 11, 12 or 10, 11 is cast a built-up structureof sheet metal plates 17 is provided which in the casting operationforms an outer mold for the cast metal. Each of the plates 17 isprovided with set-up studs or nipples 18, 19, as clearly shown in Figs.1, 2 and 3. The studs 18 and 19 are 2-. Pairs on the opposite sides ofthe plates, studs 18 being more widely spaced than the studs 19. By thismeans, when the plates are laid one upon the will be held spaced 9.requisite distance, and bolts run through apertures 20 and 21 centrallypositioned between the studs 18 and 19, respectively, will hold a stackof said plates in fixed and "spaced relation. Each plate has its innermargin bent at 22 to form vertical cylindrical portions 23 and it isfurther bent as indicated at 24 to form inwardly-turned edges whichafter the metal is cast are embedded in the cast metal, and, where-themetal of the plates and of the casting is the same, will be fused intoit, as clearly indicated in Fig. 9. If the casting material has a lowerfusing point, as, for example, aluminum cast upon steel fin plates, the

projecting edge portions 24 will not fuse with the aluminum but will befirmly embedded therein and becomesubstantially integral therewith so asto be highly effective in transmitting heat from the casting to theextended fin plates.

The cylindrical portions 23 vertical with respect to the plane of theplates 17 form in effeet a series of spacer members from one plate toanother which when the built-up structure is assembled provides acylindrical skin or layer 25 of previously-fabricated metal surroundingthe cast metal inner shell, with the fin plates extending outwardly fromsaid layer of fabricated metal and having portions projected throughsaid layer and anchored in the inner shell of cast metal. The resultingstructure, therefore, whether the cast metal and fin plates be of thesame fusibility in which case the projections will be fused into thecast metal, as in Fig. 9, or whether they be of different metals inwhich the plates may be merely firmly anchored in the cast metal, willcomprise a shell or layer of previously-fabricated metal surrounding aninner shell of cast metal, with a multiplicity of sheet metal finsextending outwardly from the shell or layer of previously-fabricatedmetal, and having portions projected through said layer and anchored inthe inner shell of cast metal.

Substantially the same result is obtained by the construction shown inFigs. 4, 5 and 6. As shown, fin plates 26 are provided with elongatedoval openings and have notches 27 stamped at various points around theinterior of that circumference whereby lugs 28 are bent at right anglesto the main body of the plates 26. Surrounding these lugs and held inposition thereby are a multiplicity of spacer rings 29, clearly shown inlongitudinal section in Fig. 6 and in cross section in Fig. 4. Previousto casting the inner shall a multiplicity of fin plates 26 and spacerrings 29 are assembled to produce, a built-up structure ofpreviously-fabricated metal of the desired length. Bolts, not shown,which extend through bolt holes 30 (the bolts being removed aftercasting) hold the built-up structure in assembled position, and there iscast within the shell or layer of built-up metal formed by the spacerrings 29 an inner shell 31 of cast metal having top and bottom walls 32also of cast metal. These walls may be perforated as indicated at 33 forthe reception of steam or hot water inlet pipes and other pipes 34 willcarry away the steam or hot water, or if desired one of the walls 32 maybe eliminated and direct gas firing applied to the structure, asindicated in Fig. 9. It will be noted that each fin plate will have aportion 34 projected into the cast metal. inner shell. These portions 34will fuse with the cast metal if it is of the same kind of metal as thefin plates or of higher fusing point,

and the fin plates will be firmly anchored in the cast metal if it has alower fusing point.

The spacer elements of the form of construction shown in Figs. 1, 2, 3and 9, and of Figs. 4, 5 and 6 are circumferential in position and buildup the outer layer or shell of previouslyfabricated metal bycircumferential increments. In the form of the invention shown in Figs.7, 8 and 10 the spacer elements are longitudinal and the fins extendlongitudinally and project radially in all directionsfrom this outerlayer or shell of previously-fabricated material. As shown, the finplates 40 are merely rectangular strips of sheet metal provided withsmall apertures 41 through which wires 42 extend. Wedgeshapedlongitudinal spacer members 43 are provided and the whole is held inassembled position by means of the wires 42, after which an inner shell44 of metal is cast in the manner disclosed in my aforesaid patent. Apreferred construction of this form of the invention casts a dividingweb 45 which terminates short of the top casting 46 which is continuouswith shell 44, leaving a space 4'7 between the end of the web 45 and thetop member 46. The bottom wall 48 in the form shown in Fig. 'l isprovided with inlet and outlet pipes 49 and 50 respectively by whichheating fluid such as steam or hot water may be caused to travel throughchamber 51, passageway 47 and back down through chamber 52 to dischargepipe 50.

In the form of the invention shown in Fig. 10, the bottom wall 48 ismodified so as to leave a free opening 53 to chamber 51 and a pipedischarge 54 from chamber 52 so that a gas burner 55 may be employed fordirect firing, the buming gas and products of combustion travelingthrough chamber 51, passageway 47, chamber 52 and discharging from pipe54.

In each of the forms above described it will be noted that there isalways provided an outer shell or layer of previously-fabricated metal,an inner shell of cast metal and sheet metal fin members havingradiating portions extended outwardly from the shell of fabricated metaland other portions projected through said fabricated shell and into theinner shell of cast metal to which they will be firmly anchored andintegrated-by actual fusing when the metals have the same fusing pointor the cast metal has a higher fusing point than the fin metal.

The advantages of this invention will clearly appear from the foregoingdescription thereof.

First and primarily, an enormous amount of radiating surface is providedin a very cheap and at the same time strong and efilcient construction.it is well-known that the transmission of heat is most effective whereit is through a continuous or integral metal body. The fin members areso thoroughly anchored and integrated to the cast metal inner shell thateven where there is not actual fusing substantially integral -metalliccontinuity is provided, and, actual metal continuity is provided wherethere is fusing. Moreover, the use of the cast metal inner core,particularly where it is cast iron, makes practical direct firing with agas flame which does not seriously deteriorate or corrode cast iron, andtherefore produces particularly efficient heat exchange.

I claim:

i. A heat exchanger comprising an inner shell of cast metal forming anenclosed chamber, a layer of previously fabricated metal surroundingsaid shell, and a multiplicity of sheet metal fins having portionsprojected through said layer. and anchored in the inner shell of castmetal.

2. A heat exchanger comprising an inner shell of cast iron forming anenclosed chamber, a layer of previously fabricated metal surroundingsaid shell, and a multiplicity of sheet iron fins having portionsprojected through said layer, .and having their inner portions fusedinto the inner shell of cast iron. 3. A heat exchanger comprisingalternating metal fin sheets and metal spacer elements, said fin sheetsembodying radiating fins extending outwardly and projections extendinginward- 1y from said spacer elements, and an inner layer of cast metalembracing and being anchored to said inward projections. v

4. A heat exchanger comprising a shell of fabricated metal, sheet metalfins having po'r- 'tions extending outwardly from said shell andothertportions extending inwardly therefrom, and a layel 0! cast metalwithin said shell embracing and anchoring said inward projections.

5. A heat exchanger comprising a shell of fabricated metal, sheet metalfins having portions extending outwardly from said' shell and otherportions projecting inwardly therefrom, and a cast metal inner portionembracing and anchoring said inward projections adjacent the cast metal.

lining of cast metal fabricated shell and formed with to provide anenclosed top and bottom portions chamber formed by the 6. A heatexchanger comprising a shell of metal, sheet metal fins having portionsextending outwardly from said shell and other portions projectinginwardly therefrom, a cast metal inner portion embracing and anchoringsaid inward projections adjacent the shell and formed with top andbottom portions to provide an enclosed chamber formed by the cast metal,and means to permit introduction and withdrawal of a heat-conveying-medium into and from said chamber.

'1. A heat exchanger comprising a multiplicity of fin plates each formedwith a central opening and having the edges surrounding saidopeningbent, substantially at right angles to the plate and inwardly, saidplates being assembled so that the bent portionsform a continuous sheetmetal shell from which fins project outwardly and,

inner portions project inwardly, and'an inner to said inner projections.

8. A heat exchanger comprising an inner cast metal portion and finplates having projections extending into said .cast metal portion andanchored thereto, each of said fin plates being offset circumferentiallyfrom said anchored portionsto form jointly an outer layer or shell.

9. A heat exchanger comprising a multiplicity of fin plates, acorresponding number of spacer members extending between the fin platesto form an outer shell orlayer of previously-fabricated metal, saidfin-plates having portions projecting inwardly from said layer, and acast metal inner shell within said layer ,of fabricated metal embracingand anchored to said inwardlyprojeeting portions of the fin plates.

10. A heat exchanger comprising a cast metal inner shell and a castmetal top, said shell hav-'- ing an enlarged opening at the bottomadapted to receive a direct gas flame and an opening embracing andanchored through said top to discharge the gas of combustion from saidflame, and fin plates having portions forming alayer of metalsurrounding said cast metal shell, and having portions thereof extendingwithin and anchored to said cast metal shell.

11. A heat exchanger comprising an elongated body. of cast metal forminga closed chamber, a layer or shell of fabricated metal surrounding saidbody and connected thereto, :and a multiplicity of longitudinal finplates extending outwardly from said layer of fabricated metal andhaving portions-extending through the same and into the cast metal andbeing anchored thereto.

12. A heat exchanger comprising a cast metal inner portion forming aclosed chamber and forming a partition dividing the chamber into twoparts with a passageway connecting said parts at one end of the chamber,one of said parts being open at its bottom for receiving directly a gasflame and the other part being connected with a pipe for dischargingthegases of combustion, and fin members formed of previously fabricatedsheet metal having portions anchored within the body of said inner castshell.

g -13. A heat exchanger comprising a shell formed of two layers ofcontacting and united metal, the inner layer being of cast metal andforming an enclosed chamber and the outer layer being composed of amultiplicity of portions of previously fabricated metal, all contactingand secured'to said layer of cast metal,

and a' corresponding number of sheet. metal 15. A heat exchangercomprising a hollow core of cast metal, sheet metal fin members havingportions entering .and anchored-to said core and other portionsextending outwardly therefrom, previously fabricated metal filling thespaces between the fin members and anchored to said cast core, and meansfor permitting introduction and withdrawal of a heatconveying mediuminto and from the hollow interior of the core.

16.'A heat exchanger comprising a multiplicity of fin plates each formedwith a central opening, spacer elements for holding said finplates'separated a predetermined distance at said central opening, eachspacer element and an adjacent plate being formed integral, said spacerelements and fin plates forming in conjunction a substantiallycontinuous wall, and a cast metal inner shell within and fused upon saidwall.

'17. A heat exchanger comprising a multiplicity of fin plates eachformed with a spacer member, said fin plates and spacer members formingconjointly an outer shell or layer of previously-fabricatedmetal, and acast metal 1 inner shell within and fused to said outer shell.

JOHN O'I'IO OLSON.

